Due to the increasing value of commodity metals, such as copper, theft of materials from heating, ventilation and air conditioning (“HVAC”) equipment is on the rise. Because material-rich elements of air conditioning systems are typically located outdoors, such elements are especially vulnerable to theft. For example, the exterior unit of a typical residential air conditioning system is located on the ground and external to any building structure. Accordingly, the exterior unit may be readily dismantled for the copper tubing therein without entering the residence itself, and often without disturbing anyone within the residence.
Moreover, such units are in many cases out of immediate plain view from the street and/or within the house. Accordingly, thieves can disassemble the external HVAC unit and remove the copper tubing without easy detection.
To address this issue, systems have been implemented to detect possible theft events in HVAC units, and provide an alarm notification thereof. Many of these systems rely on pressure sensors or movement sensors that indicate when a portion of the air conditioning system is being manipulated or compromised. For example, U.S. Pat. No. 8,001,797 shows a theft detection device that includes a pressure sensor that detects when pressure within the air conditioning line is compromised, thereby indicating a possible theft condition. U.S. Pat. No. 7,812,734 shows a system that detects when copper lines to an air conditioner unit are disconnected or cut, by testing electrical continuity in the copper lines.
Each of these systems has complexity and cost in installation that inhibits their widespread use. For example, the installation of pressure sensors in existing systems, or existing designs of systems, undesirably requires the introduction of parts directly into the pressurized refrigerant line. In addition, testing for tubing electrical continuity requires specialized wiring and interconnection. Many systems further require specific precision installation to avoid making the theft prevention system immune to tampering. For example, U.S. Patent Application Publication No. 2012/0200413 shows a system that tests continuity of a sensor wire that runs to the exterior HVAC unit. That system requires the sensor wire to be taut to avoid quick reconnection by the thief.
There is a need, therefore, for an HVAC theft detection and notification system and method that does not involve expensive or precision installation techniques.